Apparatus for drying printed webs of material



March 5, 1963 A. M. HALLEY EIAL 3,079,702

I APPARATUS FOR DRYI NG PRINTED WEBS OF MATERIAL Filed April 10, 1959 2Sheets-Sheet l Inventor: ANGUS muRRA HALLEF LEio/UARD ERNEST STAPLE F RDsmwgma {wall A ttorneys March 5, 1963 A. M. HALLEY ETA!- 3,079,702

APPARATUS FOR DRYING PRINTED WEBS 0F MATERIAL Filed April 10, 1959 2Sheets-Sheet 2 Inventor ANGUS MURRAY HALLEY LEM W E A/Esq" T%PLEFORD'hmfi mm man? A ttorneys Ue t d s t C 3 9 ,702 v APPARATUS FOR DRYINGPRINTED WEBSOFMATERIAL Angus Murray Halley and Leonard ErnestStapleford, Birmingham; England, as' signors to James Halley & seasLimited,- West Brornwich, England, a British com- Filed Apr. 10, 1959,Ser. No; 805,551 Claims priority,papplication Great Britain Apr. 18,1958 a 11 Claims. (Cl. 34-86) T his invention has reference to apparatusfor drying printed webs or material and has forit's object to provideimproved apparatus for drying the web through v the agency ofhot aircurrents in such manner that the heat content of the air currents istransferred to the web with high efficiency. V

The invention consists of apparatus for drying a continuously movingprinted web of material including a rotatable drum for the support of apart of the length of the web, a plurality of tubular electric heatersdisposed adjacent to that part of the exterior surface of the drum whichcarries the web, and arranged to direct jets of hot air on to the web asshown by the arrows of FIGURE 2, acasing for the support of the tubularheaters in relation to the drum which casing in conjunction with thedrum defines a path for the flow of air to the heaters and a path for apart of the hot air subsequentto its impingement on the web, into theinterior of the drum thereby to heat the drum internally to assist thedryingof the webpart thereon, and fan means for circulating the airthrough the casing in the aforesaid manner;

Preferred means for carrying the invention into prac tice' will now' bedescribed by way of example with reference to the accompanying drawings,wherein:

' FIGURE 1 is a sectional elevation of a drying unit according to theinvention substantially along line 11 in FIGURE 2, u l V FIGURE 2 isapart sectional end elevation of the unit substantially along' line 22of FIGURE 1, and

' FIGURE 3 is an enlarged cross-sectional View of one of the heaterunits as illustrated in' FIGURE 1.

The apparatus seen in the drawings incorporates a rotatable drumcomprising a hollow Cylindrical wall 3 which issupported at eachendonthe rim of a spoked wheel-like member 4 the hub 4a whereof is rotatablymounted by anti-friction bearings on a tubular shaft 5 which is fixed atits ends in a casing.

The casing comprises a pair of shells 6 and 6 one about each end of thedrum 3 and an arcuate cover plate 18 of cylindrical form extendingbetween and secured to shells 6 and 6 radially outwardly of cylindricalWall 3 of the drum. The periphery of each shell is rotatably mounted ina ring 7 on a standard 8 of the printing machine to permit an angularadjustment of the position of the shells 6 and 6 relative to the drum 3for the purpose of adjusting the angular position of an arcuate array oftubular heater units 9 relative to the part of the web 10 in contactwith the surface of the drum. Thus when the apparatus is mounteddirectly above the printing cylinder of the printing machine, by theangular adjustment of the heater array relative to the drum, the heaterarray may be displaced to either side of the vertical centre line of theprinting cylinder at will, according to the direction in which theprinted web is being delivered.

Each of the heater units 9 generally comprises a tubular housing 32incorporating a plenum accommodating an electric heating element 34 andthe tubular housing of the heater is adapted to admit air at one endthereof so that the air can be forced through the plenum over theheating element therein and thence through slots 30 in 3,679,792 e M i?73 ice the housing to impinge on the web of material in" the form ofjets of hot aif. g V I A'plurality of parallel tubular heaters oftheaforesaid type are supported between annular flanges on the two shells 6and 6' so asto form an arcuate array covering about one third of thec'ircumference of the drum, and in order to supply air to the tubularhe'aters the shell 6 at one end of the apparatus defines in conjunctionthe standard 8' an inlet chamber 11 of annular shape haY-f ing an inletport 12 for the admittance of air into the chamber 11 and an outlet port13 communicating with the end of each tubular heater 9. H I g The heaterarray is externally screened by the arcuate cover plate 18 mountedbetween the two shells 6 and 6 in order to confine the hot air currentfrom the heaters 9 in the vicinity ofthe web; p

According to the present invention the hot air subse'- quent to itsimpingement on the web of material is directed in part through theinterior of the drum. This effect is achieved by providing ports 14 and14' (FIG- URE- 2) in the said flanges of she1ls'6 and 6', respec{ tivelybetween the ends of each tubular heater 9 mounted thereon to permit theflow of air from the ends of the annular region between the heater arrayand the exterior of the drum 3 into spaces 15:? and 15b defined between"the shells and the en s or the" drum. At the endof th'e drum remotefromthe air inlet chamber" 11 'the air drawn from the said end space1511, through the spoke'd wheel support 4 into and through the drum andthence;

into the space iSb'defined between the second spoked wheel support andthe shellincorporating the air inlet" to atmosphere at 21 or mayberecirculated viathe inlet chamber through the above described flow path;

'Desirably a helical battle 19 is mounted extrinauymr the periphery ofthe exhaust chamber and is" adapted to provide increase'd'heat exchangebetween the unearneding through the exhaust chamber 16 and the indentincold air passing through the inlet member 11 ac'commje: dating thebafiie and to more uniformly distribute the incoming air to the heater9.

It will be appreciated that by drawing heated air subsequent toimpingement on the web to be dried through the interior of the drum 3,the cylindrical wall of the drum underlying the web will be heatedwhereby the web 10 of material thereon is heated by conduction from thedrum wall to the web in addition to the heat imparted to the web by thehot air jet from the tubular heaters 9.

The circulation or re-circulation of air through the apparatus ispromoted by a blower fan (not shown) connected to the inlet chamber 11of the casing and/or a suction fan 20 connected to the exhaust chamber16.

Subsequent to its passage beneath the heater array the web of printedand dried material is led off the rotating drum 3 over rollers 17 to awinding cylinder or other apparatus.

What is claimed is:

1. In apparatus for drying a continuously moving printed web, arotatably mounted hollow drum over the surface of which the web ispassed with the printed side outmost, hollow air heating meansexternally extending generally longitudinally of the drum adjacent thedrum, means for continuously introducing air to be heated into theinterior of said hollow heating means, said heating means having meansfor discharging heated air onto the printed surface of the web passingbetween the drum and the heating means, means for confining anddirecting at least part of said heated air after impingement on the 3web into the interior of said drum to thereby heat the drum surfaceunderlying the web, and means for continuously exhausting air from theinterior of the drum.

2. In the apparatus defined in claim 1, said air introduction-means andsaid air exhausting means-being in heat exchange relation to preheattheincoming air.

3. In the apparatus defined in claim 1, said means for directing heatedair into the drum comprising means for directing said heated air into anend of the drum.

4. In the apparatus defined in claim 1, said air exhausting meanscomprising a conduit operatively connected to one end of the drum, andthe air introduction means'comprising an annular passage surroundingsaid exhaust conduit.

. 5. In the apparatus defined in claim 4, a helical baffle membermounted on the exhaust conduit and extending into said passage forincreased heat exchange.

6. In an apparatus for drying a continuously moving printed web ofmaterial, ahollow-drum for supporting at the exterior surface thereof apart of the length of said web and being mounted for rotation about afixed axis, acasing receiving said drum, a plurality of heaters arrangedperipherally with respect to said drum within said casing with eachheater having a tubular housing extending longitudinally with respect tosaid axis and electrical heating means in said housing, said heatersbeing supported by said casing adjacent to that part of the exteriorsurface of said drum which carries said web, means for admitting airinto the interior of each of said housings to be heated bysaidelectric'heating means, means permitting the discharge of heated airfrom said housings in the form of jets for impingement on said web, airflow directing means including portions of said drum andsaid casing forconfining and directing at least part of said heated air afterimpingement on said web into the interior of said drum to thereby heatthe drum surface underlying said web, means permitting the exhaust ofair from the interior of said drum, and means for forcibly circulatingthe air in the aforesaid manner.

7. The apparatus defined in claim 6 wherein said means for admitting airinto the interior of said heaters comprises an air inlet duct in fluidcommunication with the interior of said casing and wherein said meanspermitting the exhaust of air from the interior of said drum comprisesan exhaust duct in fluid communication with the interior of said drumand being disposed in heat exchange relationship with said inlet duct.

8. In an apparatus for drying a continuously moving printed web ofmaterial, a hollow drum for supporting at the exterior surface thereof apart of the length of said web and being mounted for rotation about afixed axis, a casing having a pair of shells substantially enclosing theopposite ends of said drum and an arcuate cover plate supported by saidshells radially outwardly of said drum, a plurality of heaters arrangedperipherally with respect to said drum within said casing with eachheater having a tubular housing extending longitudinally of said axisand electric heating means in said housing, means providing at least oneair inlet in each of said housings for admitting air into the interiorof each housing to be heated by said electric heating means, saidheaters being supported by said casing adjacent to that part of theexterior surface of said drum which carries said web, means permittingthe discharge of heated air from each of said housing in the form ofjets for impingement on said web, air passage means in said shells forconfining and directing the admission of air to be heated to the inletsof each of said housings and for confining and directing at least partof said heated air after impingement on said web into the interior ofsaid drum to therebyheat the drum surface underlying the web, and meansfor continuously exhausting air from the interior of said drum, saidarcuate cover plate being so disposed to confine the heated airdischarged from said heaters. to the vicinity of the exterior surface ofsaid drum.

9. The apparatus defined in claim 8 comprising a shaft secured betweensaid shells and means rotatably mounting said drum on said shaft. I

10. The apparatus defined in claim 8 wherein said air passage means forconfining and directing air to be heated to the inlets of said housingscomprises: an inlet duct formed in one of said shells and 'a plnralityof apertures in said one shell establishing fiuid communication betweensaid inlet duct and the inlets of said housings.

11. The apparatus defined in claim 8 comprising means adjustablyrotatably mounting said casing about an axis coaxial to the rotationalaxis of said drum to enable adjustment of the angular position of saidheaters with respect to said drum.

References Cited in the file of this patent UNITED STATES PATENTS1,715,830 Glinka June 4, 1929 2,091,805 Chuse Aug. 31, 1937 2,622,343Metc'alfe Dec. 23, 1952 2,896,336 Shoumatofi July 28, 1959 2,964,854Kiefer et al Dec. 20, 1960

1. IN APPARATUS FOR DRYING A CONTINUOUSLY MOVING PRINTED WEB, AROTATABLY MOUNTED HOLLOW DRUM OVER THE SURFACE OF WHICH THE WEB ISPASSED WITH THE PRINTED SIDE OUTMOST, HOLLOW AIR HEATING MEANSEXTERNALLY EXTENDING GENERALLY LONGITUDINALLY OF THE DRUM ADJACENT THEDRUM, MEANS FOR CONTINUOUSLY INTRODUCING AIR TO BE HEATED INTO THEINTERIOR OF SAID HOLLOW HEATING MEANS, SAID HEATING MEANS HAVING MEANSFOR DISCHARGING HEATED AIR ONTO THE PRINTED SURFACE OF THE WEB PASSINGBETWEEN THE DRUM AND THE HEATING MEANS, MEANS FOR CONFINING ANDDIRECTING AT LEAST PART OF SAID HEATED AIR AFTER IMPINGEMENT ON THE WEBINTO THE INTERIOR OF SAID DRUM TO THEREBY HEAT THE DRUM SURFACEUNDERLYING THE WEB, AND MEANS FOR CONTINUOUSLY EXHAUSTING AIR FROM THEINTERIOR OF THE DRUM.